Protoplanets of the Jovian planets could have grown very hot from
A) heat from the sun.
B) radioactivity of light elements such as hydrogen and helium.
C) the infall of material at high velocity.
D) tidal forces due to the sun.
E) collisions with large planetesimals.

Question

Quizplus · Accepted Answer

The infall of material at high velocity would have caused the protoplanets to heat up due to the conversion of kinetic energy into thermal energy.

Protoplanets of the Jovian Planets Could Have Grown Very Hot